The invention relates to preparing imidazo[1,5-a]pyridinium ion fluorophores and detecting cations and hydrophobic components.
Small molecule fluorophores are becoming important tools for visualizing analytes of biological relevance. Quantitative data about the analytes is often obtained by detecting changes in the fluorescence emission of select probe molecules that bind them, which can result from photoinduced electron transfer (PET) or intramolecular charge transfer (ICT). The fluorophores that are often used for these analyses are BODIPY, coumarin, naphthalimide, and fluorescein. Although these fluorophores theoretically can be modified to display either a ratiometric dual-emission response through ICT, or a change in fluorescence intensity through PET, modifying the structure of these compounds to selectively control the excited-state photophyscial properties of these compounds typically requires multi-step synthetic operations that result in low yields.
For fluorescent probes to operate successfully and universally in a biological system, the probe must exhibit water solubility, insensitivity to local polarity, and minimal interference from background emission. These requirements are difficult to achieve.